Seasonal prevalence of cockroach species in outdoors-public facilities, the public garden and graveyard etc, were investigated by eye watching and trapping from 2000 through 2002, in Minato-ku, Tokyo. Two species including the Smoky-brown cockroach, Periplaneta fuliginosa and the Japanese cockroach, P. japonica were found in those facilities. The Smoky-brown cockroaches were frequently observed from July trough October, while that of the Japanese cockroaches peaked on April, May, October and November. By the trapping method, small sized nymphs (2-4mm pronotum) of the Smoky-brown cockroach were captured, while 4-8mm for the Japanese cockroach.

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Around Lake Suwa, Nagano Prefecture, the massive flights of chironomid midges have occurred frequently, and caused a nuisance problem for neighboring residents, business activities and tourism. In order to control adult midges, we studied the time of flight and dispersal range (vertical) of chironomid midges at the Research and Education Center for Inlandwater Environment, Shinshu University from April 18 to 20 and June 5 to 7, 1989, June 5 to 6, 1999, and September 4 to 6, 2000. Light traps were set at different heights (i.e., 1m, 9m and 16m roof). Chironomus plumosus midges were trapped most at height of 16m at any time. On the other hand, Chironomus dissidens were largely trapped at height of 9m. The time of flight was checked every 2hr during the investigation periods. In the case of C. plumosus, the flight activity reached the peak at 18:00-20:00 in spring and fall, while 18:00-6:00 in summer. In the case of C. dissidens, the peak was from 18:00 to 20:00 during the emergence periods. It was concluded that the vertical flight range were different among species and the flight time of C. plumosus showed a seasonal variation.

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I analyzed the processes of contamination of carcasses of the white-toothed shrew, Crocidura dsinezumi, or the house mouse, Mus musculus, in dog-food. Four items of examination were essential for the determination of the processes: 1) identification of carcasses, 2) determination of freshness of the carcasses, 3) detection of tooth marks or holes made by the animals on the packages, and 4) detection of feces of the animals in the packages. I divided the cases into three major processes: contaminations 1) at the complainers (e.g., a shrew in a package imported from Australia), 2) at the mills (e.g., a mummy mouse in a package without a hole), and 3) on the ways from the mills to the complainers (e.g., three mummy mice in a package with a hole).

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Catalase activity was qualitatively observed in two species of insects (Blattella germanica and Musca domestica) after different periods of immersion in a series of phosphate buffer solutions (pH 2.2, 3.0, 4.0, 5.0, 6.0, 7.0, 8.0). The catalase reaction was detected by dropping 3% hydrogen peroxide water solution on the crushed insect body. In B. germanica, catalase activity was lost after 10 days in the buffer solution at pH 2.2, 15 days at pH 3.0, 30 days at pH 4.0. The catalase activity was also lost after 20 days at pH 2.2 in M. domestica. On the other hand, the catalase activity was maintained for 30 days in B. germanica and M. domestica soaked in other solutions. The egg-cases of B. germanica immersed in each solution maintained the catalase activity for 30 days.

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[in Japanese]

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